The present invention relates in general to the construction of containers and receptacles which begin in a flat cardboard form and include score lines for folding into an upright free-standing configuration. More particularly, the present invention relates to how such fold-up containers may be made liquid-tight and secured in their folded three-dimensional form using a flexible tie, such as a strap, cable, string or cord.
The use of flat cardboard forms with fold (score) lines as a means to direct conversion of a flat (two-dimension) form into a three-dimensional stand-alone structure is well known. For example, the following patents show different structures which can be created by folding an originally flat form of cardboard into some object such as a toy house:
______________________________________ U.S. Pat. No. Patentee Issue Date ______________________________________ 4,643,697 Sheffer 02/17/1987 4,643,349 Sheffer 02/17/1987 4,608,799 Hasegawa 09/02/1986 3,315,868 Hempfling 04/25/1967 2,020,196 Mallgraf 11/05/1935 1,918,375 Bowersock et al. 07/18/1933 1,064,124 Beaumont 06/10/1913 ______________________________________
In each of the foregoing listed patents, the cardboard is folded and interconnected with tabs and slots in order to establish and maintain the free-standing, three-dimensional form for the container or structure.
In yet another group of prior references, the originating flat form of cardboard is folded along the score lines and secured by cord, cable, string or similar strap so as to maintain the three-dimensional form. Representative of this construction approach are the following patents:
______________________________________ U.S. Pat. No. Patentee Issue Date ______________________________________ Des. 117,833 Laine 11/28/1939 1,392,110 Blascheck 09/27/1921 ______________________________________
In those designs where a string, cord or strap is used to secure the folded flat form into a three-dimensional shape, a couple of different techniques are employed. The general idea is to thread a flexible cord through some or all of the folded-together portions and secure the free ends of the cord so that the folded, upright condition is maintained.
While one desirable feature of the prior references is the convenience of packaging, handling and shipping of flat forms over three-dimensional structures, one concern is how to adequately seal the edges and corners in order to make any container or receptacle of this type liquid-tight. Another concern is how to securely hold the form in its folded-up configuration so the container sides do not collapse under the weight and pressure of the contents. This will be a concern whether the contents are liquid thereby exerting a constant pressure on the side walls or dry material which may exert pressure as the load shifts during any handling or transportation.
Even if the objective in certain instances is not to create a liquid-tight container, it is important to create a rigid and strong container such that regardless of the contents, the three-dimensional form is maintained and the contents retained in their intended manner.
In designs represented by certain prior references, the corners of square or rectangular containers are created by a plurality of folds of triangular web sections. Typical of this design approach are the structures disclosed by the following patents:
______________________________________ U.S. Pat. No. Patentee Issue Date ______________________________________ 4,019,675 Andersson et al. 04/26/1977 3,207,357 Schmitt 09/21/1965 3,140,037 Baum et al. 07/07/1964 2,792,165 Thompson 05/14/1957 2,643,812 Lange 06/30/1953 1,959,613 Carson 05/22/1934 170,991 Conover 12/14/1875 ______________________________________
While a wide range and variety of construction options and configurations are disclosed by the foregoing references, the present invention provides a unique and novel combination of construction features heretofore not utilized. Virtually any flat-fold cardboard structure will provide the benefits of ease of shipping, handling and storage, due simply to its flat, two-dimensional form enabling easy stacking and conservation of space. The real value though of a particular construction design is found in the manner of converting or transforming the generally two-dimensional form into its stand-alone three-dimensional shape and in the strength, rigidity and durability of the final formed container or receptacle, whether for liquid retention or dry storage.
Another concern with fold-up containers of this type is that if they are designed as they are often are to be reusable, there are certain benefits to be derived by the ease or quickness of creating the folded-up shape as well as the ease or quickness in collapsing the three-dimensional form back to its flat form. For this reason, flat-form cardboard containers which are folded along score lines but then stapled or glued to hold their three dimensional form do not provide acceptable options for reusable containers. Anyone who has tried to disassemble a cardboard box which has been glued or stapled knows the difficulties and the fact that one or more of the cardboard panels or flaps typically tear to the point that they are unusable. For this reason the present invention focuses on the use of securing arrangements for the three-dimensional form which can be reversed so as to return the container to its flat form without any destruction of the container or partial destruction such that it is returned to its original form without any noticeable adverse side effects.
Regarding what is disclosed by the prior references and understanding what is desired for this type of container construction, the present invention is not anticipated by any prior reference and is unobvious over any prior reference or combination of references.